In a water molecule, the oxygen atom and hydrogen atoms share electrons in covalent bonds, but the sharing is not equal. In the covalent bond between oxygen and hydrogen, the oxygen atom attracts electrons a bit more strongly than the hydrogen atoms.
Answer : The activation energy for the reaction is, 119.7 J
Explanation :
According to the Arrhenius equation,
or,
![\log (\frac{K_2}{K_1})=\frac{Ea}{2.303\times R}[\frac{1}{T_1}-\frac{1}{T_2}]](https://tex.z-dn.net/?f=%5Clog%20%28%5Cfrac%7BK_2%7D%7BK_1%7D%29%3D%5Cfrac%7BEa%7D%7B2.303%5Ctimes%20R%7D%5B%5Cfrac%7B1%7D%7BT_1%7D-%5Cfrac%7B1%7D%7BT_2%7D%5D)
where,
= rate constant at 271 K
= rate constant at 281 K = 
= activation energy for the reaction = ?
R = gas constant = 8.314 J/mole.K
= initial temperature = 271 K
= final temperature = 281 K
Now put all the given values in this formula, we get:
![\log (\frac{2K_1}{K_1})=\frac{Ea}{2.303\times 8.314J/mole.K}[\frac{1}{271K}-\frac{1}{281K}]](https://tex.z-dn.net/?f=%5Clog%20%28%5Cfrac%7B2K_1%7D%7BK_1%7D%29%3D%5Cfrac%7BEa%7D%7B2.303%5Ctimes%208.314J%2Fmole.K%7D%5B%5Cfrac%7B1%7D%7B271K%7D-%5Cfrac%7B1%7D%7B281K%7D%5D)
Therefore, the activation energy for the reaction is, 119.7 J
The answer is enough solvent to make 1.00 L of solution. Since molarity is the number of moles of solute in one liter of solution, adding 0.500 mole solute to one liter solvent might not result to a solution with one liter total volume. Less than one liter solvent is first added to dissolve 0.500 mole solute and then the solution is carefully filled with more solvent until the solution reaches to one liter total volume. Hence, the resulting solution is a 0.500M concentration.
Answer : The concentration of 
ion is 0.0375 M.
Explanation :
The balanced equilibrium reaction will be:
The expression for solubility constant for this reaction will be,
![K_{sp}=[Pb^{2+}][Cl^-]^2](https://tex.z-dn.net/?f=K_%7Bsp%7D%3D%5BPb%5E%7B2%2B%7D%5D%5BCl%5E-%5D%5E2)
Now put all the given values in this expression, we get:
![2.40\times 10^{-4}=[Pb^{2+}]\times (0.0800)^2](https://tex.z-dn.net/?f=2.40%5Ctimes%2010%5E%7B-4%7D%3D%5BPb%5E%7B2%2B%7D%5D%5Ctimes%20%280.0800%29%5E2)
![[Pb^{2+}]=0.0375M](https://tex.z-dn.net/?f=%5BPb%5E%7B2%2B%7D%5D%3D0.0375M)
Therefore, the concentration of ion is 0.0375 M.
